Compilare: user.cpp: In function ‘int dfs(int, int)’: user.cpp:79:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int &p=ptr[nod]; p<g[nod].size(); p++){ ^ user.cpp: In function ‘int main()’: user.cpp:114:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.in","r",stdin); ^ user.cpp:115:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.out","w",stdout); ^